Cygnus A (3C 405)
Cygnus A (3C 405) is the strongest extragalactic radio source and third strongest radio source in the sky (after the Sun and Cassiopeiae
A). At one time believed to be the result of a collision of two galaxies,
it has now been identified as a classic double-lobed radio
galaxy that, at optical wavelengths, is a 15th magnitude cD galaxy (a
supergiant elliptical) lying about one
billion light-years away in the constellation Cygnus.
|Cygnus A (3C 405) 4.8 GHz VLA map courtesy of C. Carilli